Cyrix 486DRx2 33/66

[black_monolith]

Does anyone know what these are selling for these days? I've wasn't really able to find much of a selling history on either eBay or this forum.

[CPUShack]

usually $40-$55

[black_monolith]

I just picked up one of these for about that price. As an added bonus it has the original Cyrix heatsink and at least in the photos looked to be in very nice condition. Does the retail heatsink increase the value at all?

[CPUShack]

not a whole lot, maybe $5 or so

[feipoa]

[black_monolith]

This is my take on it:

These chips were late to market (late 1994?), and they under delivered on performance. Plus, they were expensive (undercut by competitors like Evergreen, Improve-It Technologies and Kingston). In addition to all that, Cyrix didn't get good yields on the 33/66MHz parts so those came out even later and were always in short supply.

The 33/66 was the one that everyone wanted, because 20 and 25MHz busses killed the performance on the 20/40 and 25/50 models. The 33/66 has always been expensive and hard to get. I remember even in 1999 or 2000 people were paying $50 for them on eBay. I lost auctions on them frequently.

While not as rare as something like a cx5x86-133, they are still pretty hard to find. Recently, I saw them pop up only 2-3 times per year, usually with a price of around $100 loose. They are in demand by retro enthusiasts because they are one of the fastest upgrades you can get for a 386.

[feipoa]

$100 is a realistic eBay value. Sometimes it is easy to forget how many years have passed since last checking on eBay. Look at the mad rate Voodoo 3/4/5 cards have gone up in only the past 5 years.

Was the 33/66 really the most in demand in the past? Or is it more in demand from a collection or retro gamer stand-point? Seems like if you had an 386 running at 25 MHz, you'd be itching for a 50 MHz clock speed, with the 33 MHz people wanting to wait things out a bit and then just upgrade the whole system. I'm only speculating and in actuality, have no idea what demand was like in 1994 for these.

Did the 50 MHz model come with a heatsink as well?

[CPUShack]

[black_monolith]

I believe the 40 and 50mhz models also had heatsinks.

As long as I've been aware of these chips (the late 90s), it's always been a fight to get the 66MHz part. Back then they were wanted for legitimate use by people who still ran 386 systems.

I know that at least some of the 66MHz models were brain damaged by people who tried to run them at 80MHz in their 40MHz 386s. An 80MHz part was always something 386 owners wanted, because the 40MHz bus did wonders.

[feipoa]

I'm a little surprised that Evergreen didn't market the 3.6 V SXL2 for 80 MHz operation. Perhaps because TI wouldn't qualify them at this speed for whatever reason.

[Chook]

These chips came in the box with the heatsink separate. So I guess many of them didn't get the factory heatsink put on.

[CPUShack]

I've found many heatsinks..without chips too lol

[alexzu]

Any photos on the subj ? )

[CPUShack]

a 20/40 (one heatsink attached, one loose)

and a 66

[feipoa]

The CPUs also came with these thermal pads? Does anyone know where to source identical, or nearly identical, thermal pads?

I like the pads that IBM and Cyrix used because they tend to come off without damage to the printing on the ceramic surface of the CPU.